hartmann



(No Model.) 3 Sheets-Sheet 1.

W. G. HARTMANN.

DIE STOCK.

No. 300,604. Patented June 17, 1884,.

JNVENTOR J g w 5 E. a W? m m 3 Sheets-Sheet 2.

(No Model.)

w. o. HARTMANN.

DIE STOCK.

No. 300,604. Patented June 17, 1884.

i, f way 225% WI TNESSES (No Model.) 3 SheetsSheet 3.

W. a. HARTMANN.

DIE STOCK.

No. 800,604. Patented June 17,1884.

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NITED STATES PATENT @rrrcn.

XVILLIAM C. HARTMANN, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR OF ONE-HALF TO JOHN J. MOSSUP, OF SAME PLACE.

DIE-STOCK.

SPECIFICATION forming part of Letters Patent No. 300,604, dated June 17, 1884.

Application filed October 11. 1883. No model.)

To all whom/it may concern:

Be it known that 1, WILLIAM G. HARTMANN, of Philadelphia, Pennsylvania, and a citizen of the United States, have invented certain Improvements in Die Stocks, of which the following is a specification.

The objects of my invent-ion are, first, to improve the construction of the cutting-die; sec: ondly, to permit the ready insertion of the die into or its removal from the stock, and to hold it securely in place therein when in use third- 1y, to provide simple and efficient pawl-andratchet mechanism for operating the die; and,

. fourthly, to insurethe proper guidance of rods 1 or tubes of different sizes to be threaded.

In the accompanying drawings, Figure 1, Sheet 1, is a face view of the stock; Fig. 2, a longitudinal section of the same; Fig. 3, Sheet 2, a rear view; Fig. 4, a transverse section on the line 1 2; Figs. 5 to 12, Sheet 3, views illustrating my improved cutting-die and the novel mode of making the same; Figs. 13 and 14,,

Sheet 1, detached views of the pawls and their operating-stud; and Fig. 15, amodification'.

The casing of the stock consists of a ring, A, having at the back an internal flange, a, and at each side a projecting stud, b, to which the handles B of the stock are secured.

The die-holder consists of the two circular plates, 1) D, the former fitting snugly but so as to turn freely in the ring A, and resting on the flange a, the plate 1) bearing against the rear edge of the ring, and being recessed for the reception of the flange a, so that when the two plates are bolted together they are laterally confinedto the ring, but free to rotate in the same.

The dies F F are fitted to a central elongated opening in the holder, and consist, as usual, of threaded blocks, which, however, are made in the peculiar manner described hereinafter, and forming part. of my illVGlltiOIl.

The centering of the dies in the holder is effected by opposite set-screws c 0, carried by the holder and bearing upon the outerends of the said dies,the screws also serving, in a measure, to retain the dies in the holder, for it should be understood that the dies are simply slipped into place from the top or face of the stock, so that they can'be readily inserted or removed without the necessity of first removing a retaining cover-plat-e. Reliance for the retention of the dies in the holder is, however, mainly placed upon a bar, (1, Figs. 2 and 4, the inner edge of which is adapted to grooves sin 5 5 the sides of the dies F, the outer edge of the bar being acted upon by taper screws f, by turning which the bar may be forced into the grooves 6, so as to retain the dies, or may be permitted to leave the same when it is desired to detach the dies.

In order to permit the turning of the set screws 0 without detaching the dieflholder,

-openings g are made in the ring A, so that by turning the holder until the screws 0 are in line with these openings said screws may be readily operated by a suitable tool introduced through the openings.

The periphery of the plate D of the dieholder has teeth h, abrupt on both faces, and one of the projections 12 is made tubular for the reception of two sliding pawls, G G, the outer ends of which are acted upon by springs '5, the inner ends of the pawls being beveled that of the pawl G in one direction and that of the pawl G in the opposite direction-so that one pawl is adapted to engage with the teeth h and turn the die-holder when the ring A is turned to the right, and the other pawl when the ring is turned to the left, these de- Vices thus constituting a duplex pawl-andi'atchet mechanism. It is necessary, however, to withdraw and retain one pawl when the other is in action,-and for this purpose various means may be employed, the simplest be- 8 5 ing set-screws passing through the projection Z) and adapted to bear upon or to enter recesses in the pawls when the latter are retracted, as shown in Fig. 15. For the ready operation of the pawls, however, I prefer the device shown in Figs. 1, 2, and 14, this device consisting of a knob, H, adapted to a bearing in the projection Z), and having a pin, In, adapted to engage with slots at in the pawls, the pin and slots being so arranged that the turning 5 of the knobin one direction or the other to the required extent will effect the projection of one pawl and the retraction of the other. Thus on reference to Fig. 2 it will be observed that if the knob H is turned in the di= I00 bar upon which a thread is to be cut.

rection of the arrow, the pink will first depress the pawl G, and will then pass from the slot at of said pawl to that of the pawl G, and on continuing the movement will effect the raising or retraction of said pawl G.

A spring-catch, j, adapted to notches in the knob, or some equivalent device, should be employed to retain the said knob in its extreme positions; otherwise the springs t will depress both pawls.

The pawls may be rectangular in cross-section; but as this would necessitate the formation of a rectangular opening in the projection 12, I prefer to use pawls of the character shown in Fig. 13, these pawls being formed by simply severing longitudinally a round bar with tapered end. To prevent the pawls from turning in the projection 12, one of said pawls has a groove, n, to which is adapted the point of a pin, a. (See Fig. 2.)

When it is not desired to use the ratchet mechanism of the stock, the die-holder may be locked to the ring A by a set-screw, J.

On the rear of the plate D of the die-holder is a tubular projection, K, to which is fitted a ring, K, having projections q, corresponding with the bases of the threads in the cutting-dies, and serving as guides for the rod or This ring K is detachable, so that rings of different sizes adapted to guide-rods of different diameters may be used, the rings having tongues 8, adapted to a groove in the projec-' tion K, so that they are prevented from turning, and the maintenance of their projections q in line with the cutting-bits of the die is insured, the ring being held in position longitudinally by a setscrew.

The construction of the improved dies F, which I use in the stock, is shown in Figs. 5 to 12, Sheet 3. Each die has on the inner face two cutting-bits, w w, there being a recess, 00, outside of eachbit, and a recess, 3 between the two. The usual plan of making dies of this class is to take a block of the character shown in Fig. 5; to first drill a central hole in the same, as indicated by the dotted circle 1; then to thread the opening thus formed, as shownby the circle 2; then to drill the four holes indicated by the dotted circles 3, and finally to sever the block on the central line, .4, so as to form two dies with the desired cutting-bits w and recesses 00 and 1 The objection to this plan is that the drilling of the holes 3 leaves the teeth of the bits it with ragged ends; hence it is necessary to file out the recesses 00 and y,

.the character of the latter recess (it being half and partly in the other, as shown in Figs. 6, 7, and 8, so that when the two parts of the die are secured together by the bolt to the die, so far as the cutting-bits and recesses are concerned, will be similar to one made in the ordinary way. The halving of the dies, however, permits me to use a milling-tool to true the recess :1 as well as the recesses 00; hence the manufacture of the die is materially facilitated, a better die is produced, and the sharpening ily accomplished.

In making my improved dies I take two blocks, W -W, Fig. 9, and, after bolting the same together, form the central threaded opening, as shown in Fig. 10, and then sever the block on the central line, 4. The bolts are then removed so as to leave four segments or half-dies of the character shown in Fig. 11, in which segments the desired recesses can be readily, formed by means of a suitable millingtool, as will be seen on reference to the dotted lines in said figure. It is preferable to form on one half of the die a tongue, 1:, and on the other half a groove, 12, so as to aid the bolt a in preventing the halves of the die from shifting their position laterally, a modification of this idea being that shown in Fig. 12, in which a recess is milled in each half of the die, these recesses coinciding when the halves are bolted together and forming an opening for the re ception of a retainingpin, v.

I claim as my invention 1. The combination of the die-holder, the dies having grooves e, the retaining-bar d, adapted to said grooves, and the taper screws f, for adjusting said bar, as set forth.

2. The combination of the outer ring or casing, A, the die-holder having teeth h, and the spring-pawls G G, adapted to act upon said teeth, and sliding in a projection of the ring, with means, substantially as described, for retaining either of said pawls in a retracted position, as set forth.

3. The combination of the ring or casing A, the die-holder having teeth h, the springpawls G G, having grooves on, and the knob H, having a pin, it, adapted to said grooves, as set forth.

4. The combination of the ring or casing A, the die-holder having teeth h, the springpawls G G, having grooves m, the knob- H. having a pin, it, and means for retaining said knob in the positions to which it is adjusted, as set forth.

5. The combination of the ring or casing A, the die-holder having teeth h, and the springpawls G G, of semicircular cross-section, whereby they are adapted to a circular opening in the casing, as set forth.

6. The within-described cutting die, made in halves bolted together, as described, and having cutting-bits w, opposite recesses x, and central recesses, y, the latter being bounded of the bits when theybecome dull can be readby true segments extending to the I points of the teeth of the bits 10, as set forth.

7. The within-described cuttingdie, made in halves bolted togethe'r,2tnd having a tongueand-groove connection, said die having entting-bits w, opposite recesses w, and central recesses, y, the latter being bounded by true segments which extend to the points of the teeth forming the bits 10, as set forth.

8. The mode described of making dies for die-stocks said mode consisting in first bolting together two blocks, W W forming a central threaded opening therein transversely severing the compound block on a line passing centrally through the opening, then sepmating the parts WV W, and finally milling recesses m and 3 in each of the segments thus 1' 5 produced, so as to form thereon a cutting-bit, w, as set forth. 7

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

W'M. G. HARTMANN. Vitnesses:

JOHN E. PARKER, HARRY SMITH. 

